WINNIPEG -- Miloslav Kapsik admitted beating his wife to death with a hammer but refused to give police an explanation for the grisly killing, jurors heard Tuesday.

"I have no answer for that," he told police repeatedly in one form or another over the course of a lengthy video interview on March 21, 2010.

Kapsik, then 61, told investigators he "hears voices" but did not say whether the voices drove him to kill Ludmila Kapsik, his wife of 36 years.

"Sometimes it's something stupid and sometimes it means something," said. "It gets in my head -- talking, talking, talking -- and I can't think."

Kapsik is on trial for second-degree murder. Defence lawyers argue he was suffering from a mental disorder and is not criminally responsible for the killing.

Jurors have heard police arrived at the couple's apartment to find Ludmila, 59, dead on the living room floor and Kapsik sitting calmly on the couch. An autopsy determined Ludmila had suffered nearly 60 hammer blows to the head and another 40 or more to her body.

"There is absolutely no doubt what happened here and who is responsible," Det. Sgt. Wesley Rommel told Kapsik.

"What this is about is understanding why and being respectful of someone you've been with for nearly 40 years."

Kapsik left the question why unanswered. Kapsik said he and Ludmila were sitting on the couch watching a hockey game on television when he went to a storage room and retrieved a hammer, walked up behind Ludmila and struck her "many times."

"She fell down on to the floor," he said. "She tried to move."

Kapsik said he waited an hour to call 911 so he could "cool down a little bit." Kapsik talked in a flat monotone for the entirety of the interview, showing no fluctuations in emotion.

"I did not see any tears at all by Mr. Kapsik during any part of the interview," Rommel told jurors.

Kapsik told police he and his wife immigrated from then-Czechoslovakia in 1976 and had no family in Canada and no friends.

Prosecutors closed their case Tuesday. Lawyers for the defence will call their first witness Wednesday afternoon.